Cooking Device With Pyrolysis Function

ABSTRACT

The cooking device with pyrolysis function includes a cooking cavity, a heating means located within the cooking cavity for emitting heat, a combustion tube having a hollow portion formed to surround the heating means, the combustion tube being heated by the heating means and radiates its heat to the center of the cooking cavity, a combustion space formed between the heating means and the combustion tube in which cooking fumes are decomposed by the heat from the heating means, a fan adapted to withdraw air from the cooking cavity and to discharge a part or ail of the air through the connection tube into the combustion space, a connection tube for connecting fluid communication between the combustion tube and the fan, and a gas outlet for venting the steam and air in the combustion space to the outside of the cooking device.

FIELD OF THE INVENTION

The present invention relates to a combustion device that can removeodor-producing materials in the cooking cavity. Specifically, thepresent invention relates to a heating means in the cooking cavity thatcan cause thermal decomposition of odor-producing materials, in additionto cooking the food by radiation of its heat.

DESCRIPTION OF RELATED ARTS

When food is heated in a cooking device, steam and volatile fumes aregenerated from the food. These volatile fumes may contain carcinogenicformaldehyde and a variety of toxic materials which may be harmful tohuman health. To minimize the adverse effects of using the cookingdevice, these toxic contaminants should be prevented from spreading intothe living area of the user. Although range hoods are installed in manyhomes to vent cooking fumes, only a portion of the cooking fumes aredischarged outside and the rest may diffuse into the kitchen and otherliving areas.

A number of different ways for disposing cooking fumes such asadsorption method using activated carbon filters, a combustion method, acatalytic converter method, an ionic precipitation method, and a plasmadischarging method are well known. Among these, the combustion method ishighly effective in removing cooking fumes, which are oxidized at hightemperature to yield harmless carbon dioxide and water. Also, thecombustion method is proven to be economical and reliable enough to beused for the incineration of toxic chemical and biological wastes.

Some of the cooking ovens have self-cleaning functions to causepyrolysis at temperatures of about 400-500° C. in order to remove foodcontaminants accumulated on the wall of the cooking cavity. However, theabove case adopts a method of re-heating the cooking cavity after takingout the food and cannot solve the problem of diffusing fumes duringcooking. Therefore, a device for effectively removing contaminantsgenerated during cooking is desired.

To solve the above problems, the present invention provides cookingdevice for effectively removing cooking fumes in the cooking cavity. Anobject of the present invention is to provide an energy efficientcombustion device which includes a heating means adapted to heat up foodin the cooking cavity and to provide a cleaning effect. Another objectof the present invention is to keep the user safe from the harmfulcooking fumes by removing the fumes immediately as soon as they aregenerated in the cooking cavity.

The following patents are known in the art and are incorporated byreference herein: Korean Pat. Nos. 10-0518444; 10-0555420, 10-1203444;and U.S. Pat. Nos. 6,316,749; 6,318,245; 7,878,185; 8,101,894.

SUMMARY OF THE INVENTION

The cooking device with pyrolysis function includes a cooking cavitysurrounded by cavity walls and an oven door, a heating means locatedwithin the cooking cavity for emitting heat therefrom, a combustion tubehaving a hollow portion formed to surround the heating means, thecombustion tube being heated by the heating means and radiating its heatto the center of the cooking cavity, a combustion space formed betweenthe heating means and the combustion tube in which cooking fumes aredecomposed by the heat from the heating means, a fan adapted to withdrawair in the cooking cavity and to transfer a part or all of the airthrough the connection tube into the combustion space, a connection tubefor connecting fluid communication between the combustion tube and thefan, and a gas outlet for venting out the steam and air in thecombustion space to the outside of the cooking device.

The heating means located on the upper portion of the cooking cavitycomprises any source selected from flame generated by the oxidation offuel or a heater connected to power source.

The combustion tube has a hollow tube-type structure with a gas outletformed at one end of the combustion tube and a combustion tube inletformed at the opposite end where the heating means is connected. Theheating means is enclosed by the combustion tube. A combustion space isformed between the heating means and the combustion tube. The combustionspace and the combustion tube are heated by the heating means. Whenheated, the combustion tube radiates its heat to the center of thecooking cavity. The fumes generated during cooking are introduced to thecombustion tube to be thermally decomposed. Therefore, high energyefficiency is achieved by the heating means which has the dual functionof warming food via the combustion tube, which radiates its heat to thecooking cavity, as well as causing thermal decomposition of cookingfumes.

The fan receives power generated from a motor and forcibly convects theair within the cooking cavity. The fan is connected to the combustiontube through the connection tube and introduces the air and cookingfumes into the combustion space. The fan prevents the cooking fumes fromspreading out of the cooking cavity by maintaining alower-than-the-atmospheric pressure within the cooking cavity.

The connection tube is installed between the combustion tube and the fanand functions as a passage for a part or all of the air inhaled by thefan into the combustion space. It is desirable that the connection tubeis connected to the combustion tube near the connection tube inlet,maximizing the contacting distance of cooking fumes with the heatingmeans to improve the efficiency of the pyrolysis process.

The gas outlet is formed at one end of the combustion tube and functionsas a passage for the steam and mixed gas in the combustion tube to theoutside of the cooking device.

The cooking device further includes a temperature sensor for sensing theoperating temperature of the cooking cavity, a bottom heating meansadapted to warm the bottom portion of the cooking cavity, and an airsupply adapted to accelerate the oxidation of cooking fumes by injectingair into the combustion space.

The combustion process of contaminants in the cooking cavity is asfollows. When a heat source is supplied to the heating means to emitheat, the temperature of the combustion space and the combustion tubeincreases. As the food is warmed by the radiant heat from the combustiontube to the center of the cooking cavity, steam and fumes from the foodare generated in the cooking cavity. The fan withdraws air and fumes inthe cooking cavity, and transfer a part or all of the air and fumesthrough the connection tube into the combustion space. The cooking fumesundergo thermal decomposition (pyrolysis) in the combustion spacemaintained at 700° C. or higher temperature, and become carbon dioxideand water. The mixed gas in the combustion space travels towards the gasoutlet to be vented out of the cooking device.

BRIEF DESCRIPTION OF TUE DRAWINGS

FIG. 1 is a front view showing a cooking device 10 according to thepresent invention.

FIG. 2 is a sectional view taken along the line 2-2 of FIG. 1.

FIG. 3 is a side sectional view taken along the line 3-3 of FIG. 2.

FIG. 4 is a perspective view of some components showing a flow of airfor thermal decomposition.

DETAILED DESCRIPTION OF THE INVENTION

The objects and features of the present invention will be now made indetail to the preferred embodiments of the present invention withreference to the attached drawings.

FIG. 1 is a front view showing a cooking device 10 according to thepresent invention. An oven door 25 having a door knob 28 is rotatablyattached to an oven body 20 forming the outward appearance of the oven10. The oven door 25 seals the front side of a cooking cavity 30 toprevent volatile compounds or smells from escaping from the cookingcavity 30, to make racks easily go in and out of the cooking cavity, andto allow a user to check the progress of cooking. A control panel 22 isdisposed at one side of the front face of the oven body 20. The controlpanel 22 includes at least one controlling means for setting temperatureand time so that the inside of the cooking cavity 30 can keep a presettemperature for an appropriate period of time.

FIG. 2 is a sectional view taken along the line 2-2 of FIG. 1 showingthe inside configuration of the cooking cavity 30 and the oven body 20,and FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2.Referring to the drawings, the present invention will be described indetail as follows. The cooking cavity 30 is surrounded by a cavity wall35 and has an open front face with an interior cooking space. Thecooking cavity 30 further includes a heating means 50 mounted at theupper part of the cooking cavity 30 and a combustion tube 60 having ahollow portion formed to surround the heating means 50. The “upper part”indicates that the heating means 50 and the combustion tube 60 arelocated at the higher position than the center of the cooking cavity 30.

The combustion tube 60 has a hollow tube-type structure with a gasoutlet 90 formed at one end of the combustion tube 60 and a combustiontube inlet 62 formed at the opposite end where the heating means 50 isconnected. The heating means 50 comprises any heating source selectedfrom a flame generated by the oxidation of fuel or a heater connected toa heat source 100. A combustion space 65 is formed between the heatingmeans 50 and the combustion tube 60. The cooking fumes can undergothermal decomposition (pyrolysis) in the combustion space 65 maintainedat 700° C. or higher by the heating means 50.

As the combustion tube 60 is heated by the heating means 50, the radiantheat of the combustion tube 60 is applied to the center of the cookingcavity 30 to warm the food. Therefore, it is preferable that thecombustion tube 60 is configured to extensively circulate air in theupper portion of the cooking cavity 30 to effectively radiate its heatto the center of the cooking cavity 30.

The combustion tube 60 is selected from a group consisting of ceramics,heat-resisting metals, and a combination of both in order to withstandthe heat generated by the heating means 50. It is preferable that thecombustion tube 60 made of ceramics be enclosed by a heat resistingmetallic cover (not shown) in order to protect it from external physicalimpacts.

The cooking cavity 30 further includes a fan 70 driven by a motor forforcibly convecting the air within the cooking cavity 30. The fan 70 isa centrifugal an and is connected in fluid communication to thecombustion tube 60. The fan 70 withdraws air from the cooking cavity anddischarges a part or all of the air into the combustion space 65. When apart of the withdrawn air is discharged hack into the cooking cavity 30,the air is forcibly convected around the hot combustion tube 60resulting in a rapid increase of temperature in the cavity and cookingspeed.

The fan 70 also prevents the cooking fumes from spreading out of thecooking cavity 30 by maintaining a lower than atmospheric pressurewithin the cooking cavity 30. It is possible that the amount of airintroduced into the combustion space 65 to be controlled by the fan 70to adjust the pressure of the cooking cavity 30. The amount of cookingfumes to be pyrolyzed can also be controlled.

The connection tube 80 is installed between the combustion tube 60 andthe fan 70 and functions as a passage for a part or all of the airinhaled by the fan 70 into the combustion space 65. It is desirable thatthe connection tube 80 is connected to the combustion tube 60 near theconnection tube inlet 62, maximizing the contacting distance of cookingfumes with the heating means 50 to improve the efficiency of thepyrolysis process.

The gas outlet 90 is formed at one end of the combustion tube 60 andfunctions as a passage for the steam and mixed gas in the combustionspace 65 to the outside of the cooking device 10.

An air supply 68 and heat source 100 are installed at the connectiontube inlet 62. The air supply 68 provides fresh air into the combustionspace 65 to accelerate the oxidation of cooking fumes. The air supply 68also provides fresh air required for the oxidation of fuel in the casethe heating means 50 comprises a flame. The heat source 100 comprisesany source selected from fossil fuel or a wire connected to a powersource.

The cooking device 10 further includes a bottom heating means 55 adaptedto warm the bottom portion of the cooking cavity 30 and expedite thecooking of the food. The bottom heating means 55 comprises any heatingsource selected from flame generated by the oxidation of fuel or aheater connected to power source. It is desirable that the bottomheating means 55 be located outside of the cooking cavity 30 asillustrated in FIG. 3 if the bottom heating means 55 comprises a flame.In the case the bottom heating means 55 comprises a heater, it ispreferred that the bottom heating means 55 be installed inside of thecooking cavity 30.

The cooking device 10 further includes a temperature sensor 40 forsensing the operating temperature of the cooking cavity 30. Located atthe cavity wall 35, the temperature sensor 40 detects the changes oftemperature in the cooking cavity 30 and may turn off the operation ofthe heating means 50 or the bottom heating means 55 in the case thecooking cavity 30 is significantly above the preset temperature.

FIG. 4 is a perspective view of some components showing a flow of airfor thermal decomposition. Referring to the drawings, the combustionprocess of contaminants in the cooking cavity will be described indetail as follows.

When the heat source 100 is supplied to the heating means 50 to emitheat, the temperature of the combustion space 65 and the combustion tube60 increases. As the food is warmed by the radiant heat from thecombustion tube 60 to the center of the cooking cavity 30, steam andfumes from the food are generated in the cooking cavity 30. The fan 70withdraws air and fumes from the cooking cavity 30 and discharges a partor all of the air and fumes through the connection tube 80 into thecombustion space 65. The cooking fumes undergo thermal decomposition(pyrolysis) in the combustion space 65 maintained at 700° C. or highertemperature and become carbon dioxide and water. The mixed gas in thecombustion space 65 travels towards the gas outlet 90 to be vented outof the cooking device 10. During the preset cooking time, the heatingmeans 50 and the fan 70 are turned on so as to thermally decompose thecontaminants generated during cooking. The combustion cycle comes to anend when the heat source 100 to the heating means 50 and electricity tothe fan 70 is terminated.

As described above for the pyrolysis process of the cooking fumes, thecooking device 10 according to the present invention is efficient in useof energy because the heating means 50 has the dual function of warmingfood via the combustion tube 60, which applies its radiant heat to thecooking cavity 30, as well as causing the thermal decomposition of thecooking fumes.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the following claims.

LIST OF NUMERALS 10: Cooking device 20: Oven body 22: Control means 25:Oven door 28: Door knob 30: Cooking cavity 35: Cavity wall 40:Temperature sensor 50: Heating means 55: Bottom heating means 60:Combustion tube 62: Combustion tube inlet 65: Combustion space 68: Airsupply 70: Fan 80: Connection tube 90: Gas outlet 100: Heat source

What is claimed is:
 1. A cooking device comprising: a cooking cavity surrounded by cavity walls and an oven door; a heating means located within the cooking cavity for emitting heat therefrom; a combustion tube having a hollow portion formed to enclose the heating means, the combustion tube being heated by the heating means and radiates its heat to the center of the cooking cavity; a combustion space formed between the heating means and the combustion tube in which cooking fumes are decomposed by the heat from the heating means; a fan adapted to withdraw air from the cooking cavity and to discharge a part or all of the air through the connection tube into the combustion space; a connection tube for connecting fluid communication between the combustion tube and the fan; and a gas outlet for venting the steam and air in the combustion space to the outside of the cooking device.
 2. The oven of claim 1, wherein the heating means has the dual function of warming food via the combustion tube, which applies radiant heat to the cooking cavity, as well as causing thermal decomposition of cooking fumes.
 3. The oven of claim 1, wherein the fan prevents the cooking fumes from spreading out of the cooking cavity by maintaining a lower-than-the-atmospheric pressure within the cooking cavity.
 4. The oven of claim 1, wherein the heating means comprises any heating source selected from a flame generated by the oxidation of fuel or a heater connected to the heat source.
 5. The oven of claim 1, wherein the combustion tube is selected from a group consisting of ceramics, heat-resisting metals, and a combination of ceramics and heat-resisting metals.
 6. The oven of claim 1, further comprising an air supply adapted to inject fresh air into the combustion space.
 7. The oven of claim 1, wherein the connection tube is connected to the combustion tube near the connection tube inlet, maximizing the contacting distance of cooking fumes with the heating means to improve the efficiency of the pyrolysis process.
 8. The oven of claim 1, wherein the fan is a centrifugal fan.
 9. The oven of claim 1, further comprising a temperature sensor for sensing the operating temperature of the cooking cavity.
 10. The oven of claim 1, wherein the amount of air introduced into the combustion space is controlled by the fan to adjust the pressure of the cooking cavity or the amount of cooking fumes to be pyrolyzed.
 11. The oven of claim 1, wherein the combustion tube is located at the higher position than the center of the cooking cavity.
 12. The oven of claim 1, further comprising a bottom heating means adapted to warm the bottom portion of the cooking cavity.
 13. The oven of claim 12, wherein the bottom heating means comprises any heating source selected from flame generated by the oxidation of fuel or a heater connected to power source. 